Collaboration and Innovation Help Restore Drinking Water Resources at the Former Pease Air Force Base

By Margaret McCarthy, P.E., Brian Goetz, and Al Pratt, P.E.


Water treatment facility exterior.

The more complex a public sector project becomes, the more important cooperation, negotiation, and collaboration are in creating a path toward a viable long-term solution. These efforts are even more critical when the project involves public health along with stakeholders from federal, state, and local agencies, as well as citizens’ advocates.

This need for collaboration was very apparent in the cooperative response to the discovery of per- and poly-fluorinated alkyl substances (PFAS) in several drinking water wells near the Pease International Tradeport (Tradeport) in Portsmouth, New Hampshire, the former home of Pease Air Force Base. This system, operated by city of Portsmouth staff, is located west of the city and the city’s own water system. From the initial discovery of PFAS in the Haven Well in 2014 that caused its shutdown, to the formal dedication of a new state-of-the-art treatment facility during the summer of 2021 that brought the well back online, there were numerous instances of collaborative and innovative efforts that addressed and overcame project challenges. This article discusses the many unique approaches used over the last seven years to ensure the supply of safe, reliable drinking water to the Tradeport during the well shutdown.

History of Pease

Originally established as a municipal airport in the 1930s, the U.S. Air Force assumed control of the Pease Air Force Base from the U.S. Navy in 1951. For the duration of its time as an active-duty installation, Pease served primarily as a bomber base under the Strategic Air Command, housing the B-52 Stratofortress and other aircraft. In 1988, Pease was one of 86 military installations selected for closure by the government and was officially closed in 1991. Since then, the New Hampshire Air National Guard has been using a portion of the former airfield,1 and the Pease International Tradeport and Portsmouth International Airport have assumed control over much of the former Pease Air Force Base land for private development.

The site is now home to over 230 tenants that employ over 10,000 people, a commercial airport, the New Hampshire Air National Guard’s 157th Air Refueling Wing, a golf course, five secondary education institutions, and various restaurants and daycare facilities. Four of the city’s top 10 largest employers are located at the Tradeport and, according to one estimate, the total combined annual wages paid to the people who work at the Tradeport is about $700 million.

A Brief Primer on PFAS

Spraying firefighting foam on a fire.

Spraying firefighting foam on a fire
Source: Pixabay on Pexels

According to the U.S. Environmental Protection Agency (EPA), PFAS are a group of thousands of man-made compounds that have been manufactured and used in a variety of industries around the world since the 1940s. PFAS are persistent in the environment and in the human body – meaning they do not readily break down and can accumulate over time. Because of this persistence, one commonly used term to refer to PFAS is “forever chemicals.” If PFAS are ingested, particularly long-chain PFAS, they may be absorbed and bioaccumulate in the blood, staying in the body for long periods of time. As a result, as people are exposed to PFAS from different sources over time, the level of PFAS in their bodies may increase to the point where they may suffer from adverse health effects.2

Some of the uses of PFAS have included non-stick cookware; water-repellent clothing; stain resistant fabrics and carpets; food packaging; some cosmetics; products that resist grease, water, and oil; and firefighting foams.3

At Pease, PFAS compounds were found primarily in the firefighting foam that crews used at the fire training center at the north end of the base. During actual or simulated aircraft fires, the crews would douse the flames with a suppressant known as aqueous film-forming foam (AFFF) which contained several PFAS compounds. The excess AFFF leached into the ground and contaminated the aquifer under Pease.

After the base was closed in 1991, the base’s water system was turned over to the Pease Development Authority, the agency that oversees operations of the Tradeport. The following year, the city of Portsmouth took over operation of the water system.

Discovery of PFAS at Pease

In April 2014, the New Hampshire Department of Environmental Services (NHDES) contacted the city of Portsmouth and requested that they sample the Tradeport’s three drinking water pro[1]duction wells (Haven, Smith, Harrison) for the six most common PFAS compounds under the EPA’s Unregulated Contaminant Monitoring Program. This request was due to detections made at the base’s former fire training center and the known historical use of AFFF.

The following month, NHDES notified the city that the levels of perfluorooctane sulfonic acid (PFOS), a PFAS compound, detected in the Haven Well were 2,500 parts per trillion (ppt), about 35 times higher than the EPA’s provisional Health Advisory at the time. The city subsequently shut down the Haven Well and supplemented the lost water with approximately 500,000 gallons per day (GPD) from the Portsmouth water system. PFAS levels in the Smith and Harrison Wells were found to be below the Health Advisory, so they remained in service with monthly monitoring for PFAS. It was at this point that the investigation commenced into viable PFAS treatment options, along with options for additional long-term water supply alternatives.

Proceeding Forward

Representatives from key stakeholders evaluating design alternatives and planning response efforts.

Representatives from key stakeholders evaluating design alternatives and planning response efforts.

Based on the high levels of PFAS detected at the Tradeport, the EPA issued an Administrative Order to the Air Force in August of 2015 requiring them to come up with treatment options for both the drinking water and the underlying aquifer, as they were deemed responsible for the PFAS contamination.

The city of Portsmouth and the Air Force signed an agreement to treat PFOS and PFOA (another PFAS compound) from water supplied by the Haven, Smith, and Harrison Wells. This agreement provided the city with funds to reimburse them for the cost of design and construction of the final treatment system for all three wells. This began a two-year process of evaluating and testing appropriate and effective treatment technologies.

The Technical Response Team assembled included representatives from the:

  • City of Portsmouth and their consultants
  • Air Force Civil Engineering Center (AFCEC) and their consultants
  • Pease Development Authority
  • EPA
  • NHDES (Waste Division, Drinking Water and Groundwater Bureau)
  • New Hampshire Department of Health and Human Services
  • Agency for Toxic Substances and Disease Registry (ATSDR) Community Assistance Panel
  • Federal and state legislators
  • Pease Restoration Advisory Board
  • Haven Well Community Advisory Board
  • Others, depending on topic
Installation of the GAC filters September 2016.

Installation of the GAC filters September 2016

During much of the time the Haven Well was offline, southern New Hampshire was experiencing extreme drought conditions. With the city of Portsmouth augmenting the water supply to the Tradeport from the city’s own water system, drought conditions made that task much more difficult. Since the city’s driving goal was to ensure that they had an adequate supply of safe drinking water for both Portsmouth and the Tradeport, the parties negotiated that the city and their consultant would take the lead in investigating and implementing water treatment options for the wells. At the same time, AFCEC and their consultant would take the lead in monitoring, investigating, and implementing potential remedial options for the PFAS plume in the aquifer itself.

This division of cleanup and treatment responsibilities resulted in an example of collaboration between the federal, state, and local government agencies and their consultants. All parties involved understood that ongoing cleanup efforts of the aquifer would have unknown impacts on the almost simultaneous approach to implement a viable option for drinking water treatment. For example, if a particular remedial option for the aquifer were to result in changes to any of its various geochemical properties and the groundwater’s flow within the aquifer, it was unknown at that point what the impacts might be on viable drinking water treatment options.

The Response Team held frequent meetings, initially meeting weekly, and communicated often to plan out this multi-faceted process. They also conducted frequent water chemistry sampling of monitoring wells at various locations in the aquifer to provide additional data on which to base the designs.

Pease Tradeport Water System

2015 well sampling amounts.

The Tradeport’s water system consists of three groundwater wells (Haven, Smith, Harrison), two storage tanks, and 30 miles of water main, with demand in the system ranging from 0.4-1.3 million GPD. The system also includes a booster pump that allows water to be pumped from the lower pressure Portsmouth distribution system to the higher pressure Tradeport distribution system. In the 1980s, a water treatment facility was constructed on the base to treat for volatile organic compounds (VOCs). However, this facility was never activated due to low demand (base closure) and steadily improving groundwater quality associated with site cleanup activities. The treatment equipment was removed in 2013.

Determining Best Available Treatment

At a September 2015 meeting with AFCEC and New Hampshire Congressional members, the city proposed a pilot study using granular activated carbon (GAC) at the wellhead to treat the two active wells, Harrison, and Smith. This was done in part to monitor the effects of GAC on water corrosivity parameters and show that GAC was effective at removing PFOS and PFOA from the two wells. After successfully completing the pilot study between April and June 2016, the parties involved decided to move to a full-scale demonstration study. The full-scale study served several purposes, including proving that the results of the pilot study could scale, ensuring that proposed treatment would meet future regulatory requirements, and allowing time for the final design and construction of the treatment facility to be completed.

Installed resin filters in the treatment facility.

Installed resin filters in the treatment facility.

During the treatment technology demonstration process that began in 2016, a vendor approached the city to conduct a side-by-side pilot test of GAC and ion exchange resin on the higher PFAS concentrations in the Haven Well. Initial results showed that the resin technology significantly outperformed GAC. As pilot testing progressed, it became readily apparent that resin was continuing to outperform GAC regarding the removal of regulated compounds and unregulated short chain compounds. During the almost three years that the GAC demonstration system was in operation, the full-scale filters treated about 425 million gallons of water and showed that GAC worked well for treating the moderate levels of PFAS seen in the Harrison and Smith Wells. A cost comparison of the two media types found that the ion exchange resin, even though more costly initially, would reduce media changeout frequencies and long-term operation and maintenance (O&M) costs of the facility. Based on this information, the city’s lead consultant designed the final treatment plant using ion exchange resin for the majority of the PFAS treatment, followed by GAC polishing to treat for any legacy VOCs. AFCEC and NHDES reviewed and approved the proposed design.

Keeping the Water Flowing During Construction

Throughout the entire seven years that the Haven Well was shut down, the existing water supply system at the Tradeport needed to remain in full operation. All construction activities had to be efficiently sequenced around that requirement, minimizing the frequency and duration of any water system shutdowns. The solution to maintaining sufficient water flow into the Tradeport involved phasing construction that required close collaboration and communication between AFCEC, the city, contractors, engineers, and consultants to ensure effectively sequenced construction work.

A group photo of City of Portsmouth water operations staff.

City of Portsmouth water operations staff who ensured that adequate water quality and quantity were maintained throughout the extensive construction activities.

During construction activities, which spanned two years, from April 2019 until April 2021, city water operators continued to maintain and operate the water system. To manage this requirement and added risk, the lead consultant generated the design plans for three phases of construction. With the full-scale demonstration filters online with Harrison and Smith Wells, they designed a new building addition to house the three new GAC filter units. Once complete, they temporarily diverted flow to the new filter vessels, allowing the old demonstration filters to be removed. They also reworked the existing building to house the 12 new ion exchange resin filter vessels and a new addition to house the control room and new lab space. They started up the facility with flow from the Harrison and Smith Wells, and once proven out and approved for operation by the NHDES, restarted the Haven Well.

Another important component of project success was that all parties involved undertook an open, honest, and transparent two-way public involvement and outreach campaign throughout the life of the project via public meetings, city advisory committees, press releases, and website updates. The high-profile nature of the project and its potential impact on the lives and health of water system customers meant that community relations were not an afterthought but rather a key component of the response efforts. Those efforts included:

This sets an example going forward on how to conduct a complex project with the involvement of many different stakeholders including a highly engaged public on all levels. The entire timeline of this project, from the initial discovery of PFOS, all the way through system design, construction, and completion, was conducted in the public spotlight, including on TV and radio, in the newspapers, and elsewhere.

Formal Dedication Ceremony

Group press photo at the water treatment facility opening.

Left to right: City of Portsmouth Mayor Rick Becksted; Deputy Director of Public Works Brian Goetz; US Representative Chris Pappas; US Senator Maggie Hassan; Testing for Pease founding member Andrea Amico; US Senator Jeanne Shaheen; Acting Assistant Secretary of the Air Force for Energy, Installations, and Environment Jennifer Miller at the dedication ceremony of the Pease WTF.

The formal public dedication ceremony and press event for the new Pease Water Treatment Facility was held on May 4, 2021. Attendees included U.S. Senators Jeanne Shaheen and Maggie Hassan, U.S. Representative Chris Pappas, AFCEC program management chief Dr. Steve TerMaath, and Andrea Amico, Co-Chair of the Pease Restoration Advisory Board Community. Portsmouth Mayor Rick Becksted and Brian Goetz, Deputy Director of Public Works (DPW), represented the city. Jennifer Miller, acting Secretary of the Air Force for Energy, Installations, and the Environment, who was also present, noted that, "The standup of this plant represents not only environmental protection, but also hard work, innovative thinking, and cooperation among many stakeholders, including our federal, state, and local community partners." 4

Senator Shaheen stated, "To see this beautiful treatment plant and all of the work that’s gone into it is a testament (to) the cooperative effort that everyone has made to identify a problem and then not take no for an answer, figure out a solution, and get it done for the people of this community and it serves as a real model." Senator Shaheen added, "This has truly been a local, state, and federal project that again sets a model for the rest of the country." The DPW’s Brian Goetz lauded the numerous collaborative efforts between the Air Force and the city, noting the cooperative agreements that provided more than $17 million to add treatment for removal of PFOS and PFOA and retrofit the Pease Water Treatment Facility (WTF).

What’s Happening Now

A tour of the treatment facility.

City of Portsmouth Water Resource Manager Al Pratt leading a tour of the treatment facility as part of the dedication ceremony.

In early August 2021, the city of Portsmouth announced plans to bring the Haven Well back online, seven years after it was initially shut down. The city received permission from the NHDES for the reactivation of the well after testing at the treatment facility showed adequate PFAS treatment performance. A joint press release from the city and AFCEC stated that the city had received a permit from the NHDES that allowed the Pease WTF to "operate at full capacity with use of all the intended wells, including the Haven, Smith, and Harrison Wells."5

"Restoring the Haven Well to the city of Portsmouth water system marks another significant step in the seven year-long incremental plan, working in conjunction with the Air Force’s Civil Engineering Center to respond to the presence of PFAS contaminants that were impacting three Pease drinking water wells," said Brian Goetz. "The first milestone this year for the drinking water system was the completion of the Pease Water Treatment Facility upgrade in April. Testing and reactivation of the Haven Well is the next. The success we have achieved in filtering the Haven Well restores this supply to the drinking water system."6

GAC and resin filters.

Interior of the Pease WTF showing the resin filters in the foreground and the GAC filters in the background.

Dr. Stephen TerMaath of AFCEC’s Program Management division called the news of the Haven Well being returned to service a "major achievement for the city of Portsmouth under the leadership of city water officials. The city collaborated with all stakeholders including state and EPA regulators, engaged citizens, and elected officials to design and construct a water treatment system, with Air Force funding, using the best available technology for protection of public health."7

Since the dedication ceremony for the Pease WTF in May of 2021, the PFAS treatment system has been operating as planned. In addition, since bringing the Haven Well back online in August, the treatment facility has been in compliance with all current standards, including non-detect levels of PFAS in the plant effluent water.


A timeline of the Pease project.

Figure 1. Timeline of major milestones associated with addressing PFAS in the public drinking water wells.

Since 2014, the city of Portsmouth has been dealing with two issues challenging its ability to provide reliable drinking water to its customers – PFAS contamination and drought. City staff worked tirelessly to promote solutions and share information regarding PFAS monitoring, treatment, public education, and drought management response. They worked closely with many stakeholders including engineering consultants, NHDES, EPA, AFCEC, federal and state regulators, and concerned citizens groups in a collaborative manner to ensure that the water remained flowing. Their efforts were recognized in September 2021 when the New England Water Works Association (NEWWA) awarded the city of Portsmouth with the Distinguished Public Involvement Award for outstanding achievements, leadership, commitment, and support of professional, proactive public relations.

At the award ceremony, NEWWA Vice President James DeCelles and NEWWA Board member Thomas LeCourt recognized the city of Portsmouth "for demonstrative leadership in creating public education and information programs around emerging contaminants and drought management."

The interdisciplinary team of government officials, engineers, scientists, and construction specialists designed and installed a system that meets or exceeds all desired outcomes. Based on the accomplishments at Pease that were achieved through cooperation, negotiation, and collaboration, the results are well worth celebrating.


Margaret McCarthy HeadshotMargaret McCarthy, P.E.
Vice President
Weston & Sampson
55 Walkers Brook Drive
Suite 100
Reading, MA 01867

Brian Goetz
Deputy Director of Public Works
City of Portsmouth
680 Peverly Hill Road
Portsmouth, NH 03801


Al Pratt, P.E.
Water Resource Manager
City of Portsmouth
680 Peverly Hill Road
Portsmouth, NH 03801



1 U.S. Air Force Civil Engineer Center, Former Pease Air Force Base (BRAC 1988),
2 U.S. Environmental Protection Agency (EPA), PFOA, PFOS and Other PFAS, Basic Information on PFAS,
3 U.S. Agency for Toxic Substances and Disease Registry, What are PFAS?
4 "Innovation, partnership bring Pease water treatment plant online," Linda Geissinger, AFIMSC Public Affairs, May 12, 2021
5 City of Portsmouth, Joint Press Release with US Air Force Civil Engineering Center, "City of Portsmouth Receives Department of Environmental Services Permit to Restore Haven Well to Operation," Aug 2, 2021
6 Jeff McMenemy, "Portsmouth’s Haven well to supply water again, 7 years after PFAS contamination found," Portsmouth Herald, Aug. 3, 2021
7 Jeff McMenemy, "Portsmouth’s Haven well to supply water again, 7 years after PFAS contamination found," Portsmouth Herald, Aug. 3, 2021

This article was originally published in Journal of The New England Water Works Association in June 2022.

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